Weighing of railroad cars can be accomplished in either a static car-by-car manner, or in a dynamic in-motion manner. Typically, a large percentage of cars are weighed in a static manner on platform scales.
Mostly when railroad cars are weighed, it is primarily for accounting purposes. Although there are other essential reasons for weighing railroad cars, for example load distribution versus safety purposes, it is usually not practical to do so because of the cost and delay involved. Typically, the weighment of cars includes only those which are absolutely necessary.
There are many reasons for this. First of all, conventional platform scales are costly to install and maintain. Thus, the number of scales is limited and typically impose significant delays and cost for those cars which must be routed to them. Depending on the length of the scales and the railroad car, static weighing is accomplished by either a single draft, weighing operation, or multiple drafts. In either case, each weighment requires every car to be properly positioned on the scale platform and uncoupled from the consist, prior to weighing. Obviously, if many cars are involved, this operation is a costly and time consuming process.
Although load imbalance of railroad cars has not been necessarily considered a serious problem in the past, it is becoming important to the safety and operation of new Intermodel railroad equipment such as truck trailers on flatcars, container cars and the like. Both longitudinal, end to end, and lateral, side to side, load imbalance can affect the performance characteristics of railroad cars. The most serious, of course, results in a derailment.
Most platform scales should be capable of providing longitudinal imbalance information if each end of a car is individually weighed, but none would be able to provide lateral imbalance information as this requires each wheel of a car to be weighed separately.
Some pertinent patents are of interest. U.S. Pat. No. 3,159,227 is directed to a "Weighing Apparatus" for weighing moving loads such as railroad vehicles moving over railroad tracks. The device includes a weighing beam or rail whose strain or downward deflection as the load moves thereover is proportional to the weight of the load and is measured by any suitable means, such as strain gauges or load cells. This patent provides means supporting a weigh rail at spaced locations which permit maximum freedom of movement of the weight rail or beam during vertical deflection thereof by a load moving over a rail or beam in order that the deflection of the weigh rail not be effected by extraneous strains or forces and be proportional only to the weight of the load. The support means includes a pair of shafts rigidly secured to opposite ends of the weigh rail and resting on a rigid surface whereby the shafts may rotate or roll on the rigid surface. The shafts are rotatably mounted in housings having resilient means for permitting limited movement of the shafts toward and away from each other on the rigid surface and wherein the housings engage the shafts to prevent lateral displacement of the weigh rail.
U.S. Pat. No. 3,153,460 is directed to a "Weighing Apparatus" for weighing moving loads such as railroad cars moving along railroad tracks. The patent teaches the use of an isolated track for the weighing function to avoid the effects of expansion and contraction of the track rails. The weigh rail assembly is secured to a base between adjacent ends of spaced track rails to permit a degree of longitudinal freedom, again to avoid the effects of contraction and expansion. The isolated weigh rail is rigidly secured at its opposite end portions with the intermediate portion being free to deflect vertically downward as a load moves over the weigh rail. A weigh rail deflection sensing means is mounted in operative engagement with the weigh rail for detecting and measuring the deflection of the weigh rail. Other U.S. patents of interest are:
U.S. Pat. Nos. 2,764,399; 3,446,299; 2,914,310; 3,835,945; 3,004,152; 4,049,069; 3,009,056; 4,094,367; 3,063,635; 4,445,581; 3,284,619. PA1 1. Accounting and Billing Purposes PA1 2. Engine and Power Allocation PA1 3. Safety Purposes
An object of the present invention is to provide a new and improved weighing system for weighing moving loads, such as railroad vehicles moving over railroad tracks.
A further objective of the present invention is to provide a new and improved weighing system that is both economical, fast and easy to use.
A still further object of the present invention is to provide fast weighing of entire trains in motion.
A still further object of the present invention is to provide a weigh rail support arrangement and a load sensing arrangement which permits an automated weighing system providing both longitudinal and lateral load imbalance information.
A still further object of the present invention is to provide a new and improved technique for measuring loads on structural members.
Another important object of the present invention is to provide an inexpensive, uncomplicated, rapid weighing system that is easily installed, calibrated and monitored capable of providing both longitudinal and lateral load imbalance information.
The high cost of conventional weighing systems limits the number of units that can economically be placed in service. The relatively low cost of the present invention makes it cost effective to deploy multiple systems at multiple locations. This attribute in effect allows a railroad to bring the scale to the car rather than the car to the weighing system, and delay trains while cars are switched out and routed to remote scales.
Conventional platform scales require that each car be uncoupled from the train and individually weighed, either in single or multiple drafts. Considerable time and expense is required to weigh a complete train and additional per diem charges due to delays must be added to the direct cost of weighing. Thus, it is not often cost effective to weigh all trains. Considerable revenue can be lost due to overweight cars resulting from inaccurate or estimated tonnage.
With the load bar weighing systems according to the present invention entire trains can be rapidly weighed in-motion while routinely passing through a switch yard. The resulting data is immediately available for correcting dangerous load imbalance conditions and/or determining locomotive power required. Individual car weights can be automatically transferred to a main computer for processing. Another unique feature of the present invention is the capability of the system of providing both longitudinal and lateral load imbalance data on each car after it passes over the weighing system. To obtain complete load imbalance data, individual wheel weights must be measured and suitably processed. A platform scale will not generate this data. A feature of the present invention using a microcomputer is its capability to accept individual wheel load data and manipulate this data in a variety of combinations and for a variety of uses. Typical uses include the following:
a. Sum all wheels for total car weight PA2 b. Sum all cars for total train weight PA2 c. Sum selected cars, using vehicle identification, for automatic billing PA2 a. Sum total consist weight PA2 a. Sum the leading and trailing truck weight. If the difference between the two exceeds a predetermined figure, car flagged as warning PA2 b. Sum wheel weights on each side of a truck and compare. If the difference exceeds predetermined value, car is flagged.
Thus, the weighing of all cars, particularly those which may exhibit some troublesome handling characteristics under certain loading conditions, provides data that is quite useful and not presently available with platform scales. The capability to detect load imbalances may be used to reduce and eliminate dangerous and costly derailments.
A major advantage of the present invention is the ease and minimal cost of the weighing apparatus as compared to conventional scales. Since only a small section of track is actually used in the present invention, costly concrete pits, weighbridges and foundations are eliminated. Only minor modifications are required to install the load bar weighing system of the present invention. Due to the simplicity of the load bar concept and the completely above grade installation, calibration and maintenance is readily and easily accomplished.